This may be more than you're looking for, but here goes:
"Just install the detection system" might sound like a good / prudent thing
to do, but there are some drawbacks. With the information on the table, I
would put "Just install it" under the "blindly over-controlled" column. (
By "blind" I mean "blind with respect to what is strictly necessary" or "bl
ind w.r.t. how much control is enough control".) Be aware that when bills
come due and money gets tight, decision-makers can very easily cut the inst
allation or maintenance costs on such systems - where's the justification?
So the challenge is to develop a good understanding of what is an acceptabl
e risk: What control measures are necessary to sufficiently control the ha
zard? Where is "the line", and how far beyond the line should we be? A mo
re robust rationale than "it's easy enough to do" is to run reasonable scen
arios to describe the risk in the current scheme. What would it take to de
velop an Oxygen Deficient Condition at any one of these utility stations?
At any neighboring offices? How likely is such a scenario? For instance,
if you know it would require a very noticeable (think: loud) leak for 20 mi
n in a busy hallway, then you may reasonably conclude a detection/alarm sys
tem would be overly redundant. On the other hand, if a small bleed could r
esult in an ODH at a desk, then the detection/alarm system would seem very
justifiable.
Recognize that an alarm system is an administrative control. What action d
oes it call for someone to perform? If the detection system is connected t
o emergency ventilation or shut-offs, now we are talking engineering contro
ls. So I would urge you to work forward through the hierarchy of controls:
elimination - substitution - engineering controls - administrative contro
ls - personal protective equipment. Are there design phase (engineering co
ntrol) solutions which make the administrative control unnecessary?
A principal question here is, "If there were a problem, how would you know?
" followed by, "How likely is it that a problem occurs?"
Hope this helps,
-Nick
-----Original Message-----
From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**LIST.UVM.EDU] On Behalf Of Er
ic Clark
Sent: Thursday, July 08, 2010 10:02 AM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: Re: [DCHAS-L] DCHAS-L**At_Symbol_Here**LIST.UVM.EDU: CODE REQUIREMENTS FOR NITROGEN
UTILITY STATIONS IN A BUILDING
Vic,
Consider installing a low oxygen alarm; www.enmet.com probably has what you
need. We have a similar situation using plumbed in CO2. As far as regula
tory backup to justify this very minor expense, OSHA's General Duty Clause
29 CFR 654, 5(a)1 likely covers that - especially since you've already iden
tified the specific hazard.
Eric
Eric Clark, MS, CCHO, CHMM
Safety & Compliance Officer
Los Angeles County Public Health Lab
>>> 7/7/2010 8:44 AM >>>
We are constructing a two-story building approximately 168 ft x 32 ft x 14
ft high on the lower floor. The building will be multi-use, with offices in
one portion and maintenance facilities adjoining. There will be six utilit
y stations in the building with nitrogen piped to each utility station alon
g with other utilities. The nitrogen supply line at each utility station wi
ll be a one-inch diameter line with a ball valve, a check valve, and a glob
e valve.
Could you please alert us to any applicable codes and standards specificall
y regarding any risks associated nitrogen asphyxiation.
Thanks and best regards,
Vic
Victor H. Edwards, Ph. D., P. E.(TX)
Director of Process Safety
Aker Solutions
Tel: +1 (713) 270-2817
Mob: +1 (713) 724-0406
Fax: +1 (713) 270-3195
e-mail: vic.edwards**At_Symbol_Here**akersolutions.com
Aker Solutions Americas Inc.
3600 Briarpark Drive, Houston, Texas 77042-5206
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